Temperature

The average January temperature for the Midwest was 24.2°F, which was 1.8°F above the 1991-2020 normal. Temperatures were generally 2-8°F above normal across the upper Midwest and 1-3°F below normal across the lower Midwest (Figure 1). Statewide average temperatures ranged from 5.6°F above normal in Wisconsin to 3.0°F below normal in Missouri. The month started with unusual warmth in the central and northern Midwest before giving way to the coldest temperatures so far this winter. Multiple rounds of winter storms ushered in cold temperatures, bitter wind chills, and precipitation that affected the region from January 9 until about January 22. Overnight low air temperatures dipped to -10 to -20°F across Minnesota, Wisconsin, Iowa, Missouri, and Illinois from January 14-16 (Figure 2). Conditions were worsened by high winds that resulted in dangerous wind chill temperatures. Des Moines, Iowa, recorded two consecutive days when the wind chill reached -40°F, which has happened just six other times since records began in 1948. St. Joseph, Missouri, had two consecutive days when the wind chill reached -30°F, which has only occurred three other times since 1944. Temperatures thawed to close the month. Average temperatures during the last 10 days of January were 15-25°F above normal across the upper Midwest and 5-10°F above normal across the lower Midwest (Figure 3). On January 31, the high temperature at International Falls, Minnesota, reached 53°F. This was the first time International Falls recorded a January temperature above 50°F since record-keeping began in 1895.

Precipitation

January precipitation totaled 2.85 inches for the Midwest, which was 0.91 inches above normal, or 147 percent of normal. Precipitation was 1-5 inches above normal across the lower Midwest, southern Wisconsin, and southern Michigan, with the wettest conditions in Missouri’s bootheel and along the Ohio River (Figure 4). Conversely, conditions were drier than normal in the northwest across Minnesota, northern Wisconsin, and northern Michigan. Statewide precipitation totals ranged from 0.31 inches below normal in Minnesota to 2.28 inches above normal in Indiana. Rankings indicate Iowa recorded the 6th wettest January on record. The month oscillated from dry to wet throughout January, with multiple occasions of heavy precipitation throughout the region. Many locations had measurable precipitation on more than half the days in the month, particularly across Illinois, Indiana, Kentucky, Ohio, and Michigan. Detroit, Michigan, and St. Louis, Missouri, both tied their record for the greatest number of days with measurable precipitation in January (Figure 5). Detroit, Michigan, recorded its wettest January in 151 years with 5.25 inches. Conversely, Minneapolis, Minnesota, tied for the 6th driest January in 152 years with 0.13 inches.

Snowfall

January snowfall was highly variable across the region. The greatest snowfall was measured along a swath from western Iowa northeastward to northern Michigan, where totals ranged from 15-40 inches (Figure 6). In Waterloo, Iowa, a record 5-day snowfall total of 23.9 inches shattered the old 5-day snowfall record of 16 inches. In Moline, Illinois, 15.4 inches of snow fell on January 12, which was the 2nd highest daily total on record and only the third time over 15 inches of snow fell in a single day. Conversely, snowfall deficits of 5-20 inches were observed across Minnesota, northern Wisconsin, and Michigan’s Upper Peninsula (Figure 7). Snowfall was also below normal across a wide area from southern Illinois eastward through Ohio. Northeast Ohio, which typically receives ample lake-effect snow, had totals 5-25 inches below normal. While most lake-effected areas around the Great Lakes had normal or below-normal snowfall in January, the southern shore of Lake Michigan had above-normal conditions. An extreme lake-effect snow event affected far southwest Michigan and northwest Indiana on January 19-20 with snowfall rates of 2-3 inches per hour. As much as 2-3 feet of snow was reported in northwest Indiana (Figure 8), and a 5-10 car pileup shut down the Indiana Toll Road. A record single-day snowfall of 21.9 inches was reported in LaPorte, Indiana.

Drought

Drought significantly improved in January across the lower Midwest, while dry conditions lingered in Iowa and across the upper Midwest (Figure 9). Illinois, Indiana, Kentucky, and Ohio ended the month drought-free (Figure 10). Just 15 percent of Missouri was in drought by late January compared with 72 percent at the start of the month. Iowa remained the epicenter of drought for the region, with drought or dryness affecting 95 percent of the state (Figure 11). Drought was spotty across Minnesota and Wisconsin, with areas of severe drought intermixed with drought-free zones.

Cloud Cover and Fog

While January is known to be a gloomy time of year across the Midwest, January 2024 was notably cloudy and foggy for much of the region. The Minnesota Climatology Office noted that the average solar radiation (sunshine) in St. Paul was the lowest among all Januarys since 1963 (when record-keeping began). About 75 percent of days in January reported noontime cloud cover in Indianapolis compared to the historical average of 44 percent of days (Figure 12, Iowa Environmental Mesonet). Persistent dense fog blanketed most of the Midwest (and the larger central US) from January 23 to 25 as mild Gulf Coast air pushed across cold, moist, and snow-covered ground. Dense fog advisories covered most of the region as poor visibility disrupted flights, delayed schools, and generated hazardous driving conditions.